Methods and systems for determining body lumen size

1 . A method, comprising:

filling a balloon within a body lumen with a fluid;

detecting a fluid parameter of the fluid over a period of time;

determining a parameter curve of the fluid parameter, wherein the parameter curve includes the fluid parameter versus an independent variable over the period of time;

comparing the parameter curve of the fluid parameter to a reference curve, wherein comparing the parameter curve to the reference curve includes determining a ratio of a first independent-variable value at an inflection or an endpoint of the parameter curve to a second independent-variable value at a reference inflection or a reference endpoint of the reference curve; and

determining, based on the ratio, a size of the body lumen or a neuromodulation parameter corresponding to the size of the body lumen.

2 . The method of claim 1 further comprising:

filling the balloon with the fluid prior to inserting the balloon into the body lumen;

detecting the fluid parameter of the fluid prior to inserting the balloon into the body lumen; and

generating the reference curve based on the detected fluid parameter prior to inserting the balloon into the body lumen.

3 . The method of claim 2 , wherein the balloon is submersed in a heated water bath when filling the balloon with the fluid prior to inserting the balloon into the body lumen.

4 . The method of claim 1 , wherein the fluid parameter is a pressure of the fluid, and wherein the independent variable is time.

5 . The method of claim 1 , wherein the fluid parameter is a pressure of the fluid, and wherein the independent variable is volume of the fluid.

6 . The method of claim 1 , wherein the first independent-variable value corresponds to the inflection of the parameter curve, and wherein the second independent-variable value corresponds to the reference inflection of the reference curve.

7 . The method of claim 6 further comprising determining a nominal diameter of the balloon, wherein determining the ratio is based on the nominal diameter of the balloon being less than a predetermined body lumen size.

8 . The method of claim 1 , wherein the first independent-variable value corresponds to the end point of the parameter curve, and wherein the second independent-variable value corresponds to the reference end point of the reference curve.

9 . The method of claim 8 further comprising determining a nominal diameter of the balloon, wherein determining the ratio is based on the nominal diameter of the balloon being greater than a predetermined body lumen size.

10 . The method of claim 1 further comprising:

determining the balloon is a compliant balloon; and

wherein determining the size of the body lumen or the neuromodulation parameter corresponding to the size of the body lumen based on the comparison is in response to determining the balloon is the compliant balloon.

11 . A tissue treatment system, comprising:

a catheter comprising a balloon mounted on a catheter shaft;

one or more syringes to fill the balloon with a fluid;

a non-transitory computer readable memory storing instructions; and

one or more processors configured to execute the stored instructions to cause the tissue treatment system to:

fill the balloon with the fluid within a body lumen;

detect a fluid parameter of the fluid over a period of time;

determine a parameter curve of the fluid parameter, wherein the parameter curve includes the fluid parameter versus an independent variable over the period of time;

compare the parameter curve of the fluid parameter to a reference curve, wherein comparing the parameter curve to the reference curve includes determining a ratio of a first independent-variable value at an inflection or an endpoint of the parameter curve to a second independent-variable value at a reference inflection or a reference endpoint of the reference curve; and

determining, based on the ratio, a size of the body lumen or a neuromodulation parameter corresponding to the size of the body lumen.

12 . The tissue treatment system of claim 11 , wherein the one or more processors are further configured to execute the stored instructions to cause the tissue treatment system to:

fill the balloon with the fluid prior to inserting the balloon into the body lumen;

detect the fluid parameter of the fluid prior to inserting the balloon into the body lumen; and

generate the reference curve based on the detected fluid parameter prior to inserting the balloon into the body lumen.

13 . The tissue treatment system of claim 12 further comprising a heated water bath, wherein the one or more processors are further configured to execute the stored instructions to cause the tissue treatment system to fill the balloon when the balloon is submersed in the heated water bath prior to inserting the balloon into the body lumen.

14 . The tissue treatment system of claim 11 , wherein the fluid parameter is a pressure of the fluid, and wherein the independent variable is time.

15 . The tissue treatment system of claim 11 , wherein the fluid parameter is a pressure of the fluid, and wherein the independent variable is volume of the fluid.

16 . The tissue treatment system of claim 11 , wherein the first independent-variable value corresponds to the inflection of the parameter curve, and wherein the second independent-variable value corresponds to the reference inflection of the reference curve.

17 . The tissue treatment system of claim 16 , wherein the one or more processors are further configured to execute the stored instructions to cause the tissue treatment system to determine a nominal diameter of the balloon, wherein determining the ratio is based on the nominal diameter of the balloon being less than a predetermined body lumen size.

18 . The tissue treatment system of claim 11 , wherein the first independent-variable value corresponds to the end point of the parameter curve, and wherein the second independent-variable value corresponds to the reference end point of the reference curve.

19 . The tissue treatment system of claim 18 , wherein the one or more processors are further configured to execute the stored instructions to cause the tissue treatment system to determine a nominal diameter of the balloon, wherein determining the ratio is based on the nominal diameter of the balloon being greater than a predetermined body lumen size.

20 . The tissue treatment system of claim 11 , wherein the one or more processors are further configured to execute the stored instructions to cause the tissue treatment system to determine the balloon is a compliant balloon, and wherein determining the size of the body lumen or the neuromodulation parameter corresponding to the size of the body lumen based on the comparison is in response to determining the balloon is the compliant balloon.

21 . The tissue treatment system of claim 11 , wherein the catheter further comprises an ultrasound transducer within the balloon.

22 . A non-transitory computer readable medium storing instructions, which when executed by one or more processors of a tissue treatment system, cause the tissue treatment system to perform a method, comprising:

filling a balloon with fluid within a body lumen;

detecting a fluid parameter of the fluid over a period of time;

determining a parameter curve of the fluid parameter, wherein the parameter curve includes the fluid parameter versus an independent variable over the period of time;

comparing the parameter curve of the fluid parameter to a reference curve, wherein comparing the parameter curve to the reference curve includes determining a ratio of a first independent-variable value at an inflection or an endpoint of the parameter curve to a second independent-variable value at a reference inflection or a reference endpoint of the reference curve; and

determining, based on the ratio, a size of the body lumen or the neuromodulation parameter corresponding to the size of the body lumen.

23 . The non-transitory computer readable medium of claim 22 , wherein the instructions, when executed by the one or more processors of the tissue treatment system, cause the tissue treatment system to perform the method further comprising:

filling the balloon with the fluid prior to inserting the balloon into the body lumen;

detecting the fluid parameter of the fluid prior to inserting the balloon into the body lumen; and

generating the reference curve based on the detected fluid parameter prior to inserting the balloon into the body lumen.

24 . The non-transitory computer readable medium of claim 23 , wherein the balloon is submersed in a heated water bath when filling the balloon prior to inserting the balloon into the body lumen.

25 . The non-transitory computer readable medium of claim 22 , wherein the fluid parameter is a pressure of the fluid, and wherein the independent variable is time.

26 . The non-transitory computer readable medium of claim 22 , wherein the fluid parameter is a pressure of the fluid, and wherein the independent variable is volume of the fluid.

27 . The non-transitory computer readable medium of claim 22 , wherein the first independent-variable value corresponds to the inflection of the parameter curve, and wherein the second independent-variable value corresponds to the reference inflection of the reference curve.

28 . The non-transitory computer readable medium of claim 27 , wherein the instructions, when executed by the one or more processors of the tissue treatment system, cause the tissue treatment system to perform the method further comprising further comprising determining a nominal diameter of the balloon, wherein determining the ratio is based on the nominal diameter of the balloon being less than a predetermined body lumen size.

29 . The non-transitory computer readable medium of claim 22 , wherein the first independent-variable value corresponds to the end point of the parameter curve, and wherein the second independent-variable value corresponds to the reference end point of the reference curve.

30 . The non-transitory computer readable medium of claim 29 , wherein the instructions, when executed by the one or more processors of the tissue treatment system, cause the tissue treatment system to perform the method further comprising further comprising determining a nominal diameter of the balloon, wherein determining the ratio is based on the nominal diameter of the balloon being greater than a predetermined body lumen size.

31 . The non-transitory computer readable medium of claim 22 , wherein the instructions, when executed by the one or more processors of the tissue treatment system, cause the tissue treatment system to perform the method further comprising further comprising:

determining the balloon is a compliant balloon; and

wherein determining the size of the body lumen or the neuromodulation parameter corresponding to the size of the body lumen based on the comparison is in response to the compliant balloon.